In addition to the maximum length,
Indian Ocean distribution, and depth distribution for each species, Debelius
often gives notes on habitat, biology and behaviour. Also scattered
through the book are longer stories of interactions with fishes, notes
on conservation, dive sites, etc.

Debelius is correct with most of
his fish identifications, as he usually consults the experts when he has
a difficult species to identify. But inevitably, there are
a few mistakes (printer’s errors?). Herewith some corrections:

p. 52:
The two fish labelled Saurida gracilis are Synodus variegatus.
Saurida species have very narrow upper lips, consequently, the teeth
of the upper jaw are more obvious than in Synodus species.
Saurida gracilis also has a few irregular black blotches on the
body.

p. 53:
the two fish identified as Synodus jaculum are Synodus dermatogenys;
this species is correctly identified in the photo just above. Synodus
jaculum has 6 or 7 brown saddle-blotches on the body and a conspicuous,
round, dark brown or black blotch at the base of the tail fin.